Touchpads are input devices that typically include a resistive or capacitive sensor or sensor array configured to translate the position and motion of a user's finger or conductive object on the touchpad into positional information. This positional information can be used, for example, to control the movement of a cursor on a computer screen. Touchpads are commonly included in laptop computers and can be used instead of or in combination with a computer mouse. Touchscreens can be a transparent form of a touchpad and are typically disposed on a video screen. Touchscreens are commonly included in monitors, smart phones, portable media players, personal digital assistants (PDAs), etc., for button selection, manipulating graphical objects, and the like.
Touchpads are typically polled by a touch circuit (e.g., processor) at a relatively high polling rate so that relatively fine movements or fast movements made by a finger or stylus can be detected for accurate cursor control. High polling rates can significantly increase power consumption and reduce the overall power efficiency in touchpad systems. Power consumption considerations are of particular importance for battery-operated and/or portable devices which can experience a significantly reduced battery life or battery charge (e.g., for rechargeable batteries) as a result of high polling rates on touchpad devices.
As more battery-operated and portable electronics become more common in today's marketplace, touchpad developers and manufacturers strive to develop more power efficient designs for touchpad systems.